Stellarators with the magnetic symmetry of a tokamak

Abstract

To meet the requirements of the U.S. Stellarator Power Plant Study, a Modular Helias‐like Heliac (MHH) configuration was developed that has features in common with a quasihelically symmetric experiment proposed at the University of Wisconsin [D. Anderson and P. Garabedian, Nucl. Fusion 34, 881 (1994)]. Improvements have been made in the design of the MHH that raise the β limit, increase the confinement time, and simplify the geometry of the coils. In particular, specifications have been found for a stellarator with just two field periods that has a magnetic field spectrum B_mn close to axial symmetry. This configuration has physical properties that make it an interesting candidate for a follow‐on experiment to assess the equilibrium, stability and transport of advanced stellarators.